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/* Copyright (C) 2015-2017 Jason A. Donenfeld <Jason@zx2c4.com>. All Rights Reserved. */
#include "peer.h"
#include "device.h"
#include "packets.h"
#include "timers.h"
#include "hashtables.h"
#include "noise.h"
#include <linux/kref.h>
#include <linux/lockdep.h>
#include <linux/rcupdate.h>
#include <linux/list.h>
static atomic64_t peer_counter = ATOMIC64_INIT(0);
struct wireguard_peer *peer_create(struct wireguard_device *wg, const u8 public_key[NOISE_PUBLIC_KEY_LEN], const u8 preshared_key[NOISE_SYMMETRIC_KEY_LEN])
{
struct wireguard_peer *peer;
lockdep_assert_held(&wg->device_update_lock);
if (peer_total_count(wg) >= MAX_PEERS_PER_DEVICE)
return NULL;
peer = kzalloc(sizeof(struct wireguard_peer), GFP_KERNEL);
if (!peer)
return NULL;
if (dst_cache_init(&peer->endpoint_cache, GFP_KERNEL)) {
kfree(peer);
return NULL;
}
peer->internal_id = atomic64_inc_return(&peer_counter);
peer->device = wg;
cookie_init(&peer->latest_cookie);
if (!noise_handshake_init(&peer->handshake, &wg->static_identity, public_key, preshared_key, peer)) {
kfree(peer);
return NULL;
}
cookie_checker_precompute_peer_keys(peer);
mutex_init(&peer->keypairs.keypair_update_lock);
INIT_WORK(&peer->transmit_handshake_work, packet_send_queued_handshakes);
rwlock_init(&peer->endpoint_lock);
skb_queue_head_init(&peer->tx_packet_queue);
kref_init(&peer->refcount);
pubkey_hashtable_add(&wg->peer_hashtable, peer);
list_add_tail(&peer->peer_list, &wg->peer_list);
pr_debug("Peer %Lu created\n", peer->internal_id);
return peer;
}
struct wireguard_peer *peer_get(struct wireguard_peer *peer)
{
RCU_LOCKDEP_WARN(!rcu_read_lock_bh_held(), "Calling peer_get without holding the RCU read lock");
if (unlikely(!peer || !kref_get_unless_zero(&peer->refcount)))
return NULL;
return peer;
}
struct wireguard_peer *peer_rcu_get(struct wireguard_peer *peer)
{
rcu_read_lock_bh();
peer = peer_get(peer);
rcu_read_unlock_bh();
return peer;
}
/* We have a separate "remove" function to get rid of the final reference because
* peer_list, clearing handshakes, and flushing all require mutexes which requires
* sleeping, which must only be done from certain contexts. */
void peer_remove(struct wireguard_peer *peer)
{
if (unlikely(!peer))
return;
lockdep_assert_held(&peer->device->device_update_lock);
noise_handshake_clear(&peer->handshake);
noise_keypairs_clear(&peer->keypairs);
list_del(&peer->peer_list);
timers_uninit_peer(peer);
routing_table_remove_by_peer(&peer->device->peer_routing_table, peer);
pubkey_hashtable_remove(&peer->device->peer_hashtable, peer);
if (peer->device->peer_wq)
flush_workqueue(peer->device->peer_wq);
skb_queue_purge(&peer->tx_packet_queue);
peer_put(peer);
}
static void rcu_release(struct rcu_head *rcu)
{
struct wireguard_peer *peer = container_of(rcu, struct wireguard_peer, rcu);
pr_debug("Peer %Lu (%pISpfsc) destroyed\n", peer->internal_id, &peer->endpoint.addr);
skb_queue_purge(&peer->tx_packet_queue);
dst_cache_destroy(&peer->endpoint_cache);
kzfree(peer);
}
static void kref_release(struct kref *refcount)
{
struct wireguard_peer *peer = container_of(refcount, struct wireguard_peer, refcount);
call_rcu_bh(&peer->rcu, rcu_release);
}
void peer_put(struct wireguard_peer *peer)
{
if (unlikely(!peer))
return;
kref_put(&peer->refcount, kref_release);
}
void peer_remove_all(struct wireguard_device *wg)
{
struct wireguard_peer *peer, *temp;
lockdep_assert_held(&wg->device_update_lock);
list_for_each_entry_safe(peer, temp, &wg->peer_list, peer_list)
peer_remove(peer);
}
unsigned int peer_total_count(struct wireguard_device *wg)
{
unsigned int i = 0;
struct wireguard_peer *peer;
lockdep_assert_held(&wg->device_update_lock);
list_for_each_entry(peer, &wg->peer_list, peer_list)
++i;
return i;
}
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